Simplify the following expression: $y = \dfrac{3}{8r + 3} \div \dfrac{5}{6r}$
Dividing by an expression is the same as multiplying by its inverse. $y = \dfrac{3}{8r + 3} \times \dfrac{6r}{5}$ When multiplying fractions, we multiply the numerators and the denominators. $y = \dfrac{ 3 \times 6r } { (8r + 3) \times 5}$ $y = \dfrac{18r}{40r + 15}$